Sear mechanism for firearms



Original Filed Feb. 7, 1931 2 Sheets-Sheet l 2 Sh'eetSf-S'heet 2 May 20,l941.` D. M. WILLIAMS SEAR MECHANISM FOR FIREARMS Original Filed Feb.'7, 1931 iii Patented May 20, 194i Original application February 7,

Divided and this Z1, 1937, Serial No. 160,321

Claims.

The present invention relates to an improvement in rearms, andparticularly to searmechanisms therefor.

One of the objects of this invention is to provide a novel arrangementfor the sear and trigger mechanism such that an vindependent operativemeans furnishes the motive power for disengaging the scar from thestriker mechanism of the gun.

In the sear disengaging means, as usually provided, in the prior art,the trigger is directly coupled or indirectly coupled by means of somelever arrangement to the sear and a pull on the trigger serves todisengage the sear from the striker and fire the ann. It is obvious,therefore, ,that the trigger pull on this type of gun, had to overcomenot only the spring tending to retain the trigger in its normalposition, but also had to provide suicient force to disengage the searfrom the striker. As is well-known in the art, the notch in the strikermechanism which is normally engaged by the sear, may take various shapesand usually, a very positive engagement of the sear and striker isdesirable in order to prevent any accidental discharge of the rearm. Inthe event a deep notch is provided in the striker to be engaged by ashoulder on the sear or vice versa, the force of a strong striker springacting on this deep notch engagement would result in a very heavytrigger pull. In some cases, it may even give rise to what is known inthe art as a drag or trigger creep. In other words, the very opposite ofthe crisp trigger pull, which is desirable.

In the gun mechanism, in accordance with the present invention, aseparate scar-releasing spring is provided which is suitably tensionedby some movable part ofthe gun and is arranged to be released by thetrigger. In other words, a manual pull on the trigger does not furnishthe motive power for the sear release. This power is furnished by aseparate operative mechanism or spring, which is automatically tensionedduring the operation of other parts of the gun mechanism.

The present invention is shown particularly applied to a gun of theautomatic or self-loading type; however, it is obvious that it may beapplied with certain minor modications to a gun which is manuallyoperated, such as the ordinary conventional lever or bolt action rifle.As before pointed out, the salient characteristic of the presentinvention is to provide a separate operative mechanism or separatespring for disengaging the sear of the gun and it is largely 193i, semiNo. application August inmaterial as to just gun nism In the presentinvention, the opening movement of the bolt serves to perform thisfunction, but it is obvious that by a suitable arrangement of parts,this tensioning eiect could be obtained either by some other portion ofthe gun mechanism or by some other movement of the bolt.

One of the objects of the present invention, therefore, is to provide agun having a uniform, light and crisp trigger pull.

A further object of the invention is to provide an actuating springoperative to disengage the sear.

It is a further object of the invention to provide an operating springsuitably tensioned by a moving part of the gun mechanism and Whosestored up energy is operative to disengage the sear.

Still another object of the invention is to provide a spring operativeupon the sear to disengage the same, which is tensioned by a movablepart of the gun mechanism and released bythe trigger mechanism. y

Other objects of the invention will appear from thefollowing disclosureand drawings illustratlng the invention.

Figure 1 is a longitudinal section of a gun in accordance with theinvention, the gun mechanism being shown in the closed position ready tore.

f Figure 2 is a longitudinal section similar to l what moving part ofthe functions to tension this operating mecha- Figure 1, with the gunmechanism being shown in open position assumed after ring.

Referring to Figure 1, the gun comprises a receiver I carrying a barrel2 having a rifle bore 3. The gun carries the usual stock secured in theusual manner by screws and 5, and is provided with a guard indicated asan entity by numeral G. Positioned within the receiver I is a bolt lhaving at its forward portion a projecting member 8 adapted to engage avibrator 9. 'I'he bolt I is apertured centrally at I0 to receive aportion of the bolt mechanism cooperating therewith, the lowest Wall ofthe bolt being slotted at I I from the aperture to its periphery, thisaiording means for inserting the scar mechanism in said slot II of thebolt 1. It is understood that the bolt 'I is provided with the usualhandle or other means for a. manual operation, not shown. Mounted withinthe forward portion of the bolt aperture I0 is a striker I2 providedwith a striker point I3 adapted to engage the rim of the cartridge I4and prime or fire the same. Mounted adjacent the rear end of theaperture I8 is a striker spring compressor element I5. The forward endI8 of the element I5 has a sliding relation with the rear portion of thestriker member I2. Confined within the striker member I2 is a spring I1bearing at its front end on the forward wall I8 of the striker, and atits rear end on the front end I8 of the compressor element I5.

Mounted in the rear end of the receiver plug 26 is an ejector 2l servingto guide the bolt spring 22 encasing the elector rod at. its rear end.The plug 28 -is recessed at 23 for the purpose of seating the head 24 ofthe ejector 2|. I'his head 24 is provided with a key 25 to preventrotation of the ejector 2|. The spring 22 is seated at its rear endagainst'the face 0f the ejector head 24 and its front end in the forwardwall of the spring compressor well. 26 indicates a retaining plunger forlocking the receiver plug 28 against rotation.

lMounted in the forward end of the slot IVI is a cooking lever 21pivotally mounted on a pin 28 carried by the bolt, and adapted to engagethe striker cam 23. There is also positioned in the slot Il a sear 38,pivotally'mounted on a pin 3I carried by the bolt. The sear 38 isprovided with a notch 32 adapted to engage a corresponding notch 33 vinthe striker I2. 'I'he rear portion of the sear 30 is provided withlingers 34 adapted to engage a finger 35 on the sear lever 36 pivoted ona pin 31 carried by the bolt.

'I'he sear lever 36 vis urged into the direction equivalent to searengaging position by a spring 35a, which is suitably mounted intheXbolt, as.

shown in the drawings.

'Ihe guard 6 comprises a trigger mechanism and magazine catch. Referringto the trigger mechanism, there is provided a trigger 38 pivotallymounted on a pin 38.

Slidably mounted in an aperture 4I) in the trigger 38 is a :triggerplunger 4I cooperating with a pawl 42 adapted to engage a set 1ever 43.The lower end of the plunger 4I is apertured to receive a spring 44which urges the slidable plunger in an upward direction. The set lever43 is pivotally mounted at. 45 and is provided with a lug 46 adapted toengage tail piece 41 of the sear lever 36.

It may be noted by referring to the drawings that the sear lever 36 andthe sear 38 are so mounted and dimensioned yas Ito provide an inclinedlower face 36a to the sear lever. particularly true when the sear isdisengaged from the striker as shown in dotted line position, in Figure1.

The gun is provided with the usual box magazine 48 and mechanism to holdthe same in place. The magazine 48 is provided with a recess l48 adaptedto engage a serrated finger piece 58.

These serrations are shown at 5I. The fingerl piece 58 is provided witha projecting member 52 adapted to engage a recess 53. The finger piece58 is apertured at 54 to receive a plunger 55 pivotally mounted at 56.

The forward end 51 of the plunger bears against a spring 58. Mounted inthe fiooi platev 58 is a set spring holder 68 carrying a set lever.spring 6I. Mounted in the top portion of the set lever spring is a.plunger 62 having a ball point 63 adapted rto engage a socket 64 in theset lever. The floor plate catch 65 pivotally mounted on pin 65 engagesoor plate 58 at 61 to locate the oor plate. The iioor plate catch 65isheld This is amasar I in position by means ofthe spring 68. The floorplate catch 88 is recessed at 68 to provide a seat for pawl plunger 18actuated by the spring 1I.`

The spring 1I functions topush the plunger 18 against the pawl 42. 'I'hepawl 42 is provided with a hook 12 adapted to engage the portion 13 ofthe stirrup 14 of the set lever 43. The set lever paw! 42 is engaged atthe point I5 by the end 18 of the plunger 18.

It may be noted here that in connection with the trigger mechanism thereis a safety mechanism having a bow indicated by fthe reference numeral11, which will not be described in detail, as it is intended to be moreadequately described in another application.

The trigger mechanism is provided with means for making adjustments withregard to the trigger pull, or the amount of engagement of pawl hook 12and portion 13. To effect the adjustment, there is provided an adjustingscrew 18 which abuts against an adjusting lever 18, which has a tailpiece 88 and projecting therefrom, a forward or upper portion, notshown, which abuts against thev pawl 42. It may, therefore, be seen thatwhen the tail piece is pushed in an upward direction by movement of thescrew 18,

' that the pawl 42 will be moved to the right, and,

therefore, the hook 12 will have a shorter engagement with the portion13.

As before pointed out, plunger 4I is slidably seated in the trigger 38and is urged to an up; ward position by means of a spring 44. The upperportion of plunger 4I has a cam shoulder .8I contacting the pawl 42 atthe point 82 to provide a camming action which eliminates any back lashor looseness with respect to the trigger 38 and the pawl 42, and yforcesthe pawl 42 in close contact with the finger 83 of the trigger 38. Thetrigger 38 is held under tension by means of aV plunger 84 and plungerspring 85 mounted in adjusting lever 18.

Referring to Figure 1 of the drawings, the gunis shown in a closedposition ready to fire. Cartridge I4 has been fed in a suitable mannerand is in the chamber ready to re. Striker spring I1, bolt spring 22 andsear actuating spring 6I are all under tension. 'I'he sear shoulder 32is in engagement with the notch 33 on the striker and restrains the samefrom moving forward.

Upon apull of the trigger, pawl 42 is moved in a forward direction tothe dotted line position as shown in Figure 1, disengaging hook 12 fromthe portion 13 of set lever 43. Set lever 43 then moves in an upwarddirection to dotted line position about the pivot 45 under the 4actionof spring 6I 'I'he lug 46 integral with the set lever, therefore, ismoved in the upward direction, in turn moving tail piece 41 of the searlever in an upward direction to dotted line position against the actionof spring 35a. 'I'he rear portion of sear lever 36 is, therefore, movedin an upward direction about the pivot 31 and the front portion andfinger 35 of the sear lever therefore, moved in a downward direction.The nal position of sear lever and 1sear are also shown in dottedlinesin Figure Since the linger 35 on the sear lever engages fingers 34 onthe sear, the sear 36 is, therefore,

moved in a downward direction, swinging aboutinfluence of striker springI1 to iire the cartridge.'

. The action of the latter augmented by the action 0f the gas on thevibrator 8, serves to drive the bolt l to an open position, as shown inFigure Z. This action tensions the striker spring Il through the actionof cooking lever 21 on striker cam 29 and also tensions bolt spring 22.During the backwards motion of the bolt, the inclined face 36a of searlever 36 carried by the bolt, pushes lug $6 in a downward direction andtensions spring Si through lever $3. 'Ihe depression of lever $3 duringthe backward or opening movement of the bolt, is best seen in Figure 2,wherein set lever 53 is shown in its lowermost position, and spring 6|is shown fully compressed.

In this position, portion 13, carried by the set lever Q3 is also in aposition to be engaged by hook 12 carried by the pawl $2. Pawl 62 isurged into an engaging position by pawl plunger l actuated by spring 1l.

The bolt is now forced to a fully closed position under the action ofspring 22; however, the tension on the striker spring and the searactuating spring 6| is not fully relieved during this closing action ofthe bolt due to the engagement of the pawl hook 12 and portion i3 andthe engagement of the sear and striker notches 32 and 33. Since thetension on the sear actuating spring 6| is not fully relieved by theclosing action of the bolt, it may be noted that the possessed stored upenergy for moving the sear, as hereinbefore set forth and the pull onthe trigger is a relatively light one determined by the amount ofengagement of portion 13 and hook 12.

This application is a division of my prior application, Serial No.514,252, filed February 7, 1931.

I claim:

1. In a bolt-action firearm, the combination with the bolt-unit thereof,of a spring-pressed ring-member; a sear serving to releasably hold thesaid firing-member in its cocked position; a trigger controlling thesaid sear; spring-means urging the said sear into position to hold thesaid firing-member in its cocked position; and second spring-meansconstructed and arranged to be tensioned and relaxed by the movement -ofthe said bolt-unit and serving when tensioned to move the said sear intoposition to release the said ring-member when the said trigger isoperated.

2. In a firearm having a movable bolt, a spring-pressed ring member, asear serving to releasably hold the said firing-member in its cockedposition, a set lever constructed and arranged to move said sear torelease said ringmember, a trigger including means coacting with saidset lever to releasably hold the same in position to prevent themovement of the sear by said set lever, 'and spring means urging saidset lever into position to move said sear to release the ring-member,said spring means being constructed and arranged to be tensioned bymovement of the said bolt.

3. A sear mechanism for rearms, including in combination, aspring-pressed firing-member, a sear serving to releasably hold the saidiringmember in its cocked position, a trigger including means coactingwith the said sear to releasably hold the same in position to restrainthe said firing-member, a plunger and a spring urging said plunger tomove the said sear into its firing-member releasing position when therearm is cocked, so as to release the said firingmember when the saidtrigger is operated and means to automatically render said springoperative when said rearm is cocked.

4. In a gun having a movable bolt, a ring CFI 3 mechanism, a searconstructed and arranged to hold said tiring mechanism in cockedposition, a relatively weak spring urging said sear to holding position,a second relatively strong spring urging said sear to a releasedposition, a trigger mechanism for preventing the movement of the sear bysaid second spring, and means to tension said strong springsimultaneously movable with said bolt.

5. In a gun, a ring mechanism, a sear constructed and arranged to holdsaid firing mechanism in cocked position, a relatively weak springurging said sear to a holding position, a second relatively strongspring urging said sear to a releasing position, a movable boltmechanism carrying a cam surface constructed and arranged to tensionsaid second relatively strong spring, and a trigger mechanism forpreventing the movement of the sear by said second spring whentensioned.

6. In a gun, a striker having a notch, a spring for actuating saidstriker, a sear having a portion constructed and arranged to seat insaid notch to hold said striker in cocked position, spring means urgingsaid sear into seated position, a second spring means urging said searto a releasing position, means to tension said second spring, anautomatically movable bolt, means on said bolt for operating saidtensioning means, and a trigger mechanism for preventing the movement ofsaid sear by said second spring when tensioned.

7. In a gun having a movable bolt and a firing mechanism, a springurging said firing mechanism to firing position, means cooperating withthe firing mechanism and movable to one position to hold the ringmechanism in cocked position and movable to another position to releasethe same, means including a spring constructed and arranged to move saidholding means to release said ring mechanism when operatively tensioned,means including a. trigger constructed and arranged to prevent movementof the holding means by the spring means in one position and to allowmovement thereof in another, and means simultaneously movable with saidbolt and independently of the releasing or cooking movement of thefirst-mentioned holding means to operatively tension said spring.

8. In a gun having a movable bolt, a firing mechanism, means movable toa rst position to hold the firing mechanism in cocked position andmovable to a second position to release said ring mechanism, means tomove said holding means to the rst position, and means to move saidholding means to the second position, said last mentioned meanscomprising a spring operatively connected to said holding means andconstructed and arranged to be tensioned by a portion of the gunmechanism simultaneously movable with said bolt.

9. In a gun having a movable bolt, a ring mechanism, means movable to arst position to hold the ring mechanism in cocked position and movableto a secondposition to release said firing mechanism, a springconstructed and arranged to move said holding means to the rst positionand a second spring constructed and arranged to move said holding meansto the second position, said second spring being constructed andarranged to be tensioned by a portion of the gun mechanismsimultaneously movable with said bolt.

10. In a gun, a tiring mechanism including a striker and a spring urgingsaid striker to ring position when tensioned, means movableindependently oi said striker for tensioning said spring, meanscooperating with said striker and movable to one position to hold thestriker in cocked position and movable to another position to releasethe same, means including a spring constructed and arranged to move saidholding means to release saidv striker when operatively tensioned, meansincluding a. trigger constructed and arranged to -prevent movement oi'the hold- ,mentioned spring.

ing means by the spring means in one position and to allow movementthereof in another, und .means simultaneously movable with the means fortensioning the mst mentioned spring, and independently of the releasingor cooking movement of the holding meansto tension said second DAVID M.

